Blender file keeps crashing - how do I open it in safe mode?
You can find the terminal in Applications/Utilities and you can start blender by typing the following into a terminal window (this is the default so you may have to adjust folder names if you have altered them)

/Applications/Blender/blender.app/Contents/MacOS/blender


This may only give a simple message like Segmentation Fault

A few things you may want to try -


Turn off Load UI when opening the blend file - this will leave you in the default screen layout and not take you straight into the VSE where you where last time.
Turn off Trusted Source when opening the blend file - this will only help if you have drivers/scripts setup to run automatically
Use File->Load Factory settings before opening the blend file - this will disable non-default addons that may be causing an issue.
Also turn off Load UI and Trusted Source after loading factory defaults.
Start with a new file and import objects/animations from the bad file.